Claim: Warmer world may bring more local, less global, temperature variability

DURHAM, N.C. — Many tropical or subtropical regions could see sharp increases in natural temperature variability as Earth’s climate warms over coming decades, a new Duke University-led study suggests.

These local changes could occur even though Earth’s global mean surface air temperature (GMST) is likely to become less variable, the study shows.

A new study finds temperature variability will increase in some regions (shown in red) as Earth warms, even as global variability declines. CREDIT Duke University, Nature Climate Change

“This new finding runs counter to the popular notion that as the climate warms, temperature variability will increase and weather will get more volatile everywhere,” said Patrick T. Brown, a postdoctoral research scientist at the Carnegie Institution for Science, who led the study while he was a doctoral student at Duke’s Nicholas School of the Environment.

“Our research suggests a different scenario: Global unforced temperature variability will actually decrease, not increase, as Earth warms, but local decade-to-decade variability could increase by as much as 50 percent in some places,” Brown said.

Unforced, or natural, temperature variability can be caused by interactions between the atmosphere, ocean currents and sea ice. These fluctuations can either mask or exacerbate human-caused climate change for a decade or two at a time, he noted.

Because billions of people live in tropical or subtropical regions that may experience increased temperature variability, and because these regions are critical for biodiversity, food production and climate regulation, “it’s vital that we understand the magnitude of unforced decade-to-decade variability that could occur there, and the mechanisms that drive it,” he said.

Brown and his colleagues published their peer-reviewed paper Sept. 4 in the journal Nature Climate Change.

To conduct the study, they first inspected a climate model run under pre-industrial conditions. The model, which was developed at NOAA’s Geophysical Fluid Dynamics Laboratory, simulates climate under perpetual atmospheric conditions similar to those experienced on Earth before the widespread emission of industrial greenhouse gasses. This allows scientists to get a clearer picture of the forces that cause variability in the absence of human drivers.

“To isolate unforced variability, we looked at the model’s output without changing any of its environment parameters, such as atmospheric carbon dioxide levels, solar radiation or volcanic activity, over a theoretical 900-year timespan,” Brown explained.

On the second run, the scientists doubled the model’s atmospheric carbon dioxide levels to simulate projected future conditions.

“In the doubled-CO2 run, we saw a 43 percent decrease in global temperature variability, but with local increases of up to 50 percent in many land regions of the tropics and subtropics,” Brown said.

Consistent results were obtained using similar experiments on other climate models.

What’s happening, Brown said, is as Earth warms because of increasing CO2, there is less ice at high latitudes, which means less albedo – the less reflection of solar energy back into space.

“Albedo feedback is a large contributor to decade-to-decade unforced variability. When Earth’s atmosphere naturally gets a bit warmer, more of the reflective sea ice at high latitudes melts. This exposes more water, which absorbs solar energy and amplifies the initial warming, enhancing the GMST variability,” he explained. “But we found that when you double the CO2 levels in a climate model to mimic future conditions, the sea ice melts so much that this albedo feedback can no longer play a large role in amplifying natural temperature variability.”

The end result is less variability globally – especially in the high latitudes – but more variability in the tropics.

“This suggests that the pre-industrial control runs we have been using are not ideal for studying what unforced variability will look like in the future,” said Wenhong Li, associate professor of climate at Duke’s Nicholas School. “But it might inspire more modeling groups to run models under perpetual conditions that reflect what we expect in the future.”

“Our research suggests a different scenario: Global unforced temperature variability will actually decrease, not increase, as Earth warms, but local decade-to-decade variability could increase by as much as 50 percent in some places,” Brown said.

… could … in some places. Right. That’s very useful to know : as a non result.

I will also give my “finding” that temperature variability “could be about the same in some places”. There , and all that without the need for multi-billion dollar computer model I

this kind of wishy washy, non-committal garbage now seems to be standard fare in what claims to be science.

I thought it was because we have “The Moscow Candidate” in office? (Of course, the Russian money that flowed through various channels into the other candidate’s primary campaign meant no outside influence whatsoever…)

“Unforced, or natural, temperature variability can be caused by interactions between the atmosphere, ocean currents and sea ice. These fluctuations can either mask or exacerbate human-caused climate change for a decade or two at a time, he noted.”

Could be hotter – could be colder –
Looks like the climate scientists have covered all their bases with this prediction – Probability of being correct is 100%
Yea Team!

“Unforced, or natural, temperature variability can be caused by interactions between the atmosphere, ocean currents and sea ice. These fluctuations can either mask or exacerbate human-caused climate change for a decade or two at a time, he noted.”

We can’t isolate it. We can’t say we’ve ever actually observed it. But we know we have to stop it!

You boys are funny with you cynicism. While you make cheap fun out of every new bit of evidence, others, such as the US Department of Defence, accept the undeniable picture these incredibly powerful models are giving us.
The DoD has been sleeping, but of has woken with a vengeance and is making up that lost time. A great many of their assets are coastal – that’s a massive risk they are working to mitigate for starters.

The DoD has been sleeping, but of has woken with a vengeance and is making up that lost time. A great many of their assets are coastal – that’s a massive risk they are working to mitigate for starters.

Obama’s DOD was whipped into following every social-engineering, social-feel-good plan that his aides and appointees could come up with, including paying as much 5.00 – 60.00 per gallon of aviation fuel by the USAF to make good the White House’s “green programs.” To claim your propaganda of “rising sea levels” affecting DOD facilities, you’ll have to show me those DOD facilities that will be affected by 2 mm/year rise in sea levels. And, by the way, greater sea levels mean less dredging, more open ports, and easier dry dock accesses. Easier ship launching, easier at sea time. No affect on the USAF – other than NOT having to fake pay-off green companies and consultants for fake jet fuel. No affect on the Army. And benefits to the USN and Coast Guard – who are now wedged into the HSA anyway.

Do you want to claim that the massive, life-wasting and ineffective Rules of Engagement that so thoroughly harmed our military under Obama were “good” for anything (but our enemies), but which were NOT protested mean the US military under Obama is the “standard of excellence” against which all decisions affecting the world’s economy, cultures, health, and lifestyles are to be judged?

RACook, your last paragraph/sentence was a bit indigestible (one idea per sentence works well) but I take it you don’t agree with me.
You haven’t looked at sea level rise rate lately have you? Current estimate is more than 3mm per year – and acceleration beginning to really take off. A rise of 500mm above last century’s level by 2050 is very much on the cards. Looking into the past has shown that this sort of evolution often makes dramatic step-changes. If we take due action to avoid that we might also avoid that 500mm mark.
Whatever, we need to comprehend the problem to deal with it – and you guys aren’t helping. Though come to think of it, you’re not doing much harm either. You are collectively an unheard voice, talking to itself, here in your ghetto of religious disbelief.

“You haven’t looked at sea level rise rate lately have you? Current estimate is more than 3mm per year – and acceleration beginning to really take off. A rise of 500mm above last century’s level by 2050 is very much on the cards. Looking into the past has shown that this sort of evolution often makes dramatic step-changes. If we take due action to avoid that we might also avoid that 500mm mark.”

the accelleration which you refer to is due to the change in the method of measurement – tide gauges v satellite. The rate of accellaration for both the tide gauges and for the satellite was a double of the rate of rise over approx 100-150 years. (At least prior to the “recalberation” of the satellite measurement ) See church & White.

How will they know the climate is warming if global temperature variability is ‘masked’ or actually decreases? Without a measurable increase in average global temperatures, local variability could simply be a result of the natural variability that has always existed because of the chaotic nature of climate.

Haven’t they always told us that increasing CO2 will warm the global climate, which in turn will cause lots of nasty problems like extreme weather? How can CO2 do the later if it skips the first step and fails to measurably warm temperatures globally? What’s the mechanism? Does CO2 possess a level of intelligence that permits it to pick and choose which local areas of the planet to selectively punish with mayhem?

They seem to be going to great efforts to make climate change completely unfalsifiable. If global temperatures rise, that is proof of man-made climate change. If global temperatures are not rising, then local storms, floods, droughts, heat waves, or cold waves are proof of climate change. Since such things are always occurring someplace on the planet, there is no way to falsify the idea that man is causing the climate to change. Even if ice completely covered Canada and was moving south, they would still claim that increases in man-made emissions were causing the new Ice Age and would produce a model to demonstrate it.

So. the models , which can’t predict anything or understand anything with respect to climate, are now being examined minutely in order to to understand climate. Yeah, makes perfect sense, at least to a global warmist. We have temp data available for a century of so, and also global warming. So why didn’t they examine that data ? Answer: too much damn work.

Richard M,
The hilarity is on you my friend. That’s what humans do – they think ahead and have provisional plans for emergent situations. Our powerful ability to do that is what differentiates us from other beasts, who have limited ability in that direction. It’s why we have dominated the planet.
We’ve never needed 100% knowledge to go ahead confidently – that’s just silly.
When you laugh at the climate models, you laugh at humanity and one of its greatest achievements.

Models that can’t even hindcast accurately aren’t reliable for forecasting.
Unless they are producing the results the politicians want to see, then they are 100% accurate, regardless of what they actually produce.

“The models are our most powerful tool. How else can we look into the future?”

The IPCC would appear to disagree with you.

“In sum, a strategy must recognise what is possible. In climate research and modelling, we should recognise that we are dealing with a coupled non-linear chaotic system, and therefore that the long-term prediction of future climate states is not possible.”

Anyone who claims that a purported computer game climate simulation of an effectively infinitely large open-ended non-linear feedback-driven (where we don’t know all the feedbacks, and even the ones we do know, we are unsure of the signs of some critical ones) chaotic system – hence subject to inter alia extreme sensitivity to initial conditions, strange attractors and bifurcation – is capable of making meaningful predictions over any significant time period is either a charlatan or a computer salesman.

Ironically, the first person to point this out was Edward Lorenz – a climate scientist.

Lorenz’s early insights marked the beginning of a new field of study that impacted not just the field of mathematics but virtually every branch of science–biological, physical and social. In meteorology, it led to the conclusion that it may be fundamentally impossible to predict weather beyond two or three weeks with a reasonable degree of accuracy.

Some scientists have since asserted that the 20th century will be remembered for three scientific revolutions–relativity, quantum mechanics and chaos.

They are excellent tools for modeling something you understand perfectly.
We don’t understand the climate well enough to model it yet.
Beyond that, there’s the problem with cell size.
If you don’t know what that is, hang your head in shame and stop talking about models.

Precisely! The canonical equation chiseled in granite will do that sort of thing. Now the stuff is coming out of non earth science departments, environmental school. These days, there is a clear conflict of interest. Like the ARC Centre of Excellence in Climate Change Science isn’t going to report there is no climate change. Ditto gov departments that call themselves departments of climate change.

” One wonders if they even realize they are fake scientists doing fake science.”
There is probably a psychological term for the kind of delusion you just exhibited. I’ll have a stab at it – ‘projected bias induced delusion’.

The key word here is “may”. This is all simply armchair speculation without a single number or equation put to paper. There is no Thermodynamics, no awareness of the Gas Laws, no reference to empirical data. Unfortunately the scientific illiterati that have collected around this issue (‘global climate’) will accept anything that confirms their pre-existing biases.

Found a picture of the modeling computer. Notice the rapid variability increase, then once all the ice melts, variability decreases (then almost back-tracks on itself?). The horizontal straight line is baseline variability with a unit-less Greek value of “vu”.

There has never been any such thing as global warming. Climate is regional, and climate change is regional.

The mantra of global warming is one of political expediency, It is to create one world government.

As soon as one realizes that climate change is regional, then self interests will come to the fore, and it becomes obvious that adaption targeted to places adversely affected is the best policy. It becomes obvious that mitigation is a very silly idea.

There will be a lot of winners from climate change (assuming that change is warming), and only a few losers.

They were prepared.
The IP”CC”.
“Global Warming” got the headlines for awhile while it actually was hot in that room where Hansen testified.
“The Pause” began and the headlines became (man-made) CLIMATE CHANGE!

The message I’m getting is that the models are right even though they’re wrong. Model wrongness is due to a modeled increase in natural variability masking the model’s actual rightness. So it is because our models are right that we see them as being wrong.

For my next trick I will use a model to demonstrate that the Earth really is flat

“To conduct the study, they first inspected a climate model run under pre-industrial conditions. The model, which was developed at NOAA’s Geophysical Fluid Dynamics Laboratory, simulates climate under perpetual atmospheric conditions similar to those experienced on Earth before the widespread emission of industrial greenhouse gasses …”.
=====================
The planet was warming two centuries before ‘industrial greenhouse gasses’ could possibly have been a forcing factor.

In other words, when the global temps don’t rise as we initially claimed they would, we have an excuse and we can use local weather variations to continue to claim doomsday is nigh.

“Unforced, or natural, temperature variability can be caused by interactions between the atmosphere, ocean currents and sea ice. These fluctuations can either mask or exacerbate human-caused climate change for a decade or two at a time, he noted.”

Oh…how convenient. So the widely recognized hiatus, completely unpredicted by the models used to date, is nothing more than natural variation “masking” the global warming.

And, of course, this is based on models…which this time we can REALLY count on, in spite of the fact that they disagree with all the previous models, which we also claimed we can really count on. Because this time it’s different. Or something.

It seems to me that there’s quite a bit of local variability right now. I downloaded the GHCN tarball of global temperatures, and have calculated the monthly anomalies for several stations using the method described by Nick. First, I cut out all of the temperatures marked with -999 (the flag for “not available”), and then left out months with less than 14 days of good data. Then I calculated the monthly baselines for Jan-Dec using the period 1981-2010. Then I calculated the monthly averages for the period covered by the data and subtracted the baseline for that month to get the monthly anomaly. I plugged these values into Excel and generated a column chart and the standard deviation for the monthly anomalies.

These seemed pretty large to me, given the figures published by NOAA and such, but they sure seemed to indicate that a station of an by itself has quite a range of anomalies. This is a list of a few stations and the standard deviations of their anomalies, chosen based on the quality of data.

I further broke down the Cape Hatteras anomalies and got the standard deviations for each month for the period 2001-2016. No particular reason I used that period other than it was the 21st Century numbers. Here’s what I got:

Finally, I took the average anomaly for each year from 1970-2016 and got the delta between each year and plotted those. The standard deviation for each year’s delta was 0.8 C.

This just seems like a lot of local variation in temperature, even for the same month of the year, from year to year. As far as I can tell, the averaging that’s going on with the current calculations is damping out the true variability. How else could statements be made like “The global anomaly increased by 0.016 C from May to June.” The numbers I got for a station from year to year dwarfed such increases (and decreases).

Seriously, running codes to show this or that isn’t “research,” and it certainly isn’t science. It’s just running some computer program someone wrote and seeing what it does. If all we were interested in was how someone’s code behaved, this would have “value.” When deciding whether to discard the technological and economic advances which make life on earth wonderful, it isn’t worth s&%t. *

Lets see, the Arctic is so notoriously cloudy that the Vikings had to invent a way to estimate where the sun was in the sky by using polarization — Hence the Sunstone! The Arctic is completely dark for something like 4 to 6 months of the year, depending on the latitude. When the sun does shine, it is never overhead, always having a low sun angle. And, as I have pointed out previously, specular reflection off water, at grazing angles exceeds the albedo of snow. Actually, snow looks white, like clouds, because it is a strong diffuse reflector. That means light is reflected downward into the ice, and in all directions into the atmosphere as well as out into space. With all this, we are expected to believe that the loss of some of the ice has a significant effect on the total annual reflectivity, just because the water looks black if we don’t look at it at the right angle.

My suspicion is that the GCMs don’t model reflectivity of water properly, using an average value for high sun angles rather than taking into consideration the special geometry of the poles.

And of course, if the Arctic Sea Ice melts, it will almost certainly be the case that there will then be more cloudiness over the Arctic region (due to evaporation from what will then be open seas, rather than being ice capped as presently), and hence the albedo will increase (due to the cloudiness and less solar will reach the surface) and this will likely balance out any loss of albedo due to ice melt.

I do not consider that the so called scientists see the overall picture.

I also think that they see the globe as flat with continuous 24/7 52 weeks per year solar irradiance as depicted in the K&T energy budget cartoon. I do not consider that they sufficiently appreciate the geometry of the planet, and in particular the axial tilt.

I also consider that whilst the AGW conjecture rests upon increased forcings, the so called scientists fail to appreciate that it becomes ever more difficult to warm the planet, especially because of increased evaporation from the oceans. As Willis has demonstrated, when he reviewed the ARGO data, in the real world it is very difficult to get ocean SST above 30degC.

On the topic of local versus regional versus global variation of temperatures, can someone please explain this?
Remote, ??pristine,Macquarie Island, the site about the least influenced by the Hand of Man that I can find, looks like this over the last 50 years(though it was a little irregular before then). Raw data from Australia’s Bureau of Meteorology, acknowledged with thanks. From an Automatic Weather Station.

Agreed. I’ve done some number crunching as well, and I keep coming up with standard deviations in the anomalies that are in the 0.6-1.6 C, and some as high as 3 C, from individual stations. Given that a value would have to be outside 2 standard deviations to be statistically significant, how do they keep coming up with these “up 0.17 C for the month of July” figures?

Is this like lite beer? Less filling and tastes great? I know beer. You can’t have both. Since climate is the average of weather and weather would be variable, how does that make the average less variable? But then if I drank lite beer my mind would be clearer…nah.